
Original post:
This is an issue with the appnap feature introduced in the Mavericks update, until I fix that, please Disable App Nap for Joystick Mapper.
To do that, please do the following:
1. Locate Joystick Mapper.app in the Applications folder;
2. Control-click it;
3. Then choose "Get info";
4. Click "Prevent App Nap"
